title: Oestradiol release from self-setting apatitic bone cement responsive to plasma-calcium level in ovariectomized rats, and its physicochemical mechanism.
abstract: The effect of plasma calcium levels on the release of oestradiol from a self-setting apatite bone cement containing 0.5% oestradiol was investigated in ovariectomized rats. The profiles of in-vitro release from the cements in simulated body fluid containing 0, 5 or 10 mg calcium per 100 mL indicated that the rate of release of oestradiol decreased with increasing calcium concentration in the dissolution media. After subcutaneous implantation of oestradiol-loaded cement in healthy and vitamin D-deficient rats, oestradiol release in diseased rats with low plasma calcium levels was significantly higher than that in healthy rats. These results suggest that in-vitro release of oestradiol from apatite bone cement was dependent on the calcium concentration in the buffer and that the in-vivo release of oestradiol from apatite bone cement was dependent on plasma calcium levels.
authors.affiliation: Department of Pharmaceutical Technology, Kobe Pharmaceutical University, Higashi-Nada, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Otsuka
authors.forename: K
authors.initials: K
authors.lastname: Yoneoka
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.forename: J L
authors.initials: JL
authors.lastname: Fox
authors.forename: W I
authors.initials: WI
authors.lastname: Higuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry*; D019540:Area Under Curve; D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry*; D002118:Calcium / Q000097:blood*; D002136:Calcium, Dietary / Q000008:administration & dosage; D002626:Chemistry, Pharmaceutical / Q000379:methods; D016503:Drug Delivery Systems; D004958:Estradiol / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D014808:Vitamin D Deficiency / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D001843:Bone Cements; D002136:Calcium, Dietary; D004958:Estradiol; D002118:Calcium